gio/gmemoryinputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Christian Kellner <gicmo@gnome.org>
  21  */
  22
  23 #include <config.h>
  24 #include "gmemoryinputstream.h"
  25 #include "ginputstream.h"
  26 #include "gseekable.h"
  27 #include "string.h"
  28 #include "gsimpleasyncresult.h"
  29 #include "glibintl.h"
  30
  31 #include "gioalias.h"
  32
  33 /**
  34  * SECTION:gmemoryinputstream
  35  * @short_description: streaming input operations on memory chunks
  36  * @see_also: #GMemoryOutputStream
  37  *
  38  * #GMemoryInputStream is a class for using arbitrary
  39  * memory chunks as input for GIO streaming input operations.
  40  *
  41  */
  42
  43 struct _GMemoryInputStreamPrivate {
  44   guint8 *buffer;
  45   gsize   pos;
  46   gsize   len;
  47   gboolean free_data;
  48 };
  49
  50 static gssize   g_memory_input_stream_read         (GInputStream         *stream,
  51                                                     void                 *buffer,
  52                                                     gsize                 count,
  53                                                     GCancellable         *cancellable,
  54                                                     GError              **error);
  55 static gssize   g_memory_input_stream_skip         (GInputStream         *stream,
  56                                                     gsize                 count,
  57                                                     GCancellable         *cancellable,
  58                                                     GError              **error);
  59 static gboolean g_memory_input_stream_close        (GInputStream         *stream,
  60                                                     GCancellable         *cancellable,
  61                                                     GError              **error);
  62 static void     g_memory_input_stream_read_async   (GInputStream         *stream,
  63                                                     void                 *buffer,
  64                                                     gsize                 count,
  65                                                     int                   io_priority,
  66                                                     GCancellable         *cancellable,
  67                                                     GAsyncReadyCallback   callback,
  68                                                     gpointer              user_data);
  69 static gssize   g_memory_input_stream_read_finish  (GInputStream         *stream,
  70                                                     GAsyncResult         *result,
  71                                                     GError              **error);
  72 static void     g_memory_input_stream_skip_async   (GInputStream         *stream,
  73                                                     gsize                 count,
  74                                                     int                   io_priority,
  75                                                     GCancellable         *cancellabl,
  76                                                     GAsyncReadyCallback   callback,
  77                                                     gpointer              datae);
  78 static gssize   g_memory_input_stream_skip_finish  (GInputStream         *stream,
  79                                                     GAsyncResult         *result,
  80                                                     GError              **error);
  81 static void     g_memory_input_stream_close_async  (GInputStream         *stream,
  82                                                     int                   io_priority,
  83                                                     GCancellable         *cancellabl,
  84                                                     GAsyncReadyCallback   callback,
  85                                                     gpointer              data);
  86 static gboolean g_memory_input_stream_close_finish (GInputStream         *stream,
  87                                                     GAsyncResult         *result,
  88                                                     GError              **error);
  89
  90 static void     g_memory_input_stream_seekable_iface_init (GSeekableIface  *iface);
  91 static goffset  g_memory_input_stream_tell                (GSeekable       *seekable);
  92 static gboolean g_memory_input_stream_can_seek            (GSeekable       *seekable);
  93 static gboolean g_memory_input_stream_seek                (GSeekable       *seekable,
  94                                                            goffset          offset,
  95                                                            GSeekType        type,
  96                                                            GCancellable    *cancellable,
  97                                                            GError         **error);
  98 static gboolean g_memory_input_stream_can_truncate        (GSeekable       *seekable);
  99 static gboolean g_memory_input_stream_truncate            (GSeekable       *seekable,
 100                                                            goffset          offset,
 101                                                            GCancellable    *cancellable,
 102                                                            GError         **error);
 103 static void     g_memory_input_stream_finalize            (GObject         *object);
 104
 105 G_DEFINE_TYPE_WITH_CODE (GMemoryInputStream, g_memory_input_stream, G_TYPE_INPUT_STREAM,
 106                          G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
 107                                                 g_memory_input_stream_seekable_iface_init))
 108
 109
 110 static void
 111 g_memory_input_stream_class_init (GMemoryInputStreamClass *klass)
 112 {
 113   GObjectClass *object_class;
 114   GInputStreamClass *istream_class;
 115
 116   g_type_class_add_private (klass, sizeof (GMemoryInputStreamPrivate));
 117
 118   object_class = G_OBJECT_CLASS (klass);
 119   object_class->finalize     = g_memory_input_stream_finalize;
 120
 121   istream_class = G_INPUT_STREAM_CLASS (klass);
 122   istream_class->read  = g_memory_input_stream_read;
 123   istream_class->skip  = g_memory_input_stream_skip;
 124   istream_class->close = g_memory_input_stream_close;
 125
 126   istream_class->read_async  = g_memory_input_stream_read_async;
 127   istream_class->read_finish  = g_memory_input_stream_read_finish;
 128   istream_class->skip_async  = g_memory_input_stream_skip_async;
 129   istream_class->skip_finish  = g_memory_input_stream_skip_finish;
 130   istream_class->close_async = g_memory_input_stream_close_async;
 131   istream_class->close_finish = g_memory_input_stream_close_finish;
 132 }
 133
 134 static void
 135 g_memory_input_stream_finalize (GObject *object)
 136 {
 137   GMemoryInputStream        *stream;
 138
 139   stream = G_MEMORY_INPUT_STREAM (object);
 140
 141   if (stream->priv->free_data)
 142     g_free (stream->priv->buffer);
 143
 144   if (G_OBJECT_CLASS (g_memory_input_stream_parent_class)->finalize)
 145     (*G_OBJECT_CLASS (g_memory_input_stream_parent_class)->finalize) (object);
 146 }
 147
 148 static void
 149 g_memory_input_stream_seekable_iface_init (GSeekableIface *iface)
 150 {
 151   iface->tell         = g_memory_input_stream_tell;
 152   iface->can_seek     = g_memory_input_stream_can_seek;
 153   iface->seek         = g_memory_input_stream_seek;
 154   iface->can_truncate = g_memory_input_stream_can_truncate;
 155   iface->truncate     = g_memory_input_stream_truncate;
 156 }
 157
 158 static void
 159 g_memory_input_stream_init (GMemoryInputStream *stream)
 160 {
 161   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
 162                                               G_TYPE_MEMORY_INPUT_STREAM,
 163                                               GMemoryInputStreamPrivate);
 164 }
 165
 166 /**
 167  * g_memory_input_stream_set_free_data:
 168  * @stream:
 169  * @free_data:
 170  *
 171  **/
 172 void
 173 g_memory_input_stream_set_free_data (GMemoryInputStream *stream,
 174                                      gboolean free_data)
 175 {
 176   g_return_if_fail (G_IS_MEMORY_INPUT_STREAM (stream));
 177
 178   stream->priv->free_data = free_data;
 179 }
 180
 181 /**
 182  * g_memory_input_stream_from_data:
 183  * @data: input data.
 184  * @len: length of the data.
 185  *
 186  * Returns: new #GInputStream read from @data of @len bytes.
 187  **/
 188 GInputStream *
 189 g_memory_input_stream_from_data (const void *data, gssize len)
 190 {
 191   GInputStream *stream;
 192   GMemoryInputStream *memory_stream;
 193
 194   g_return_val_if_fail (data != NULL, NULL);
 195
 196   stream = g_object_new (G_TYPE_MEMORY_INPUT_STREAM, NULL);
 197   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 198
 199   if (len == -1)
 200     len = strlen (data);
 201
 202   memory_stream->priv->buffer = (guint8 *)data;
 203   memory_stream->priv->len = len;
 204
 205   return stream;
 206 }
 207
 208 static gssize
 209 g_memory_input_stream_read (GInputStream *stream,
 210                             void         *buffer,
 211                             gsize         count,
 212                             GCancellable *cancellable,
 213                             GError      **error)
 214 {
 215   GMemoryInputStream *memory_stream;
 216   GMemoryInputStreamPrivate * priv;
 217
 218   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 219   priv = memory_stream->priv;
 220
 221   count = MIN (count, priv->len - priv->pos);
 222   memcpy (buffer, priv->buffer + priv->pos, count);
 223   priv->pos += count;
 224
 225   return count;
 226 }
 227
 228 /**
 229  * g_memory_input_stream_get_data:
 230  * @stream:
 231  *
 232  * Returns:
 233  **/
 234 const void *
 235 g_memory_input_stream_get_data (GMemoryInputStream *stream)
 236 {
 237   g_return_val_if_fail (G_IS_MEMORY_INPUT_STREAM (stream), NULL);
 238
 239   return stream->priv->buffer;
 240 }
 241
 242 /**
 243  * g_memory_input_stream_get_data_size:
 244  * @stream:
 245  *
 246  * Returns:
 247  **/
 248 gsize
 249 g_memory_input_stream_get_data_size (GMemoryInputStream *stream)
 250 {
 251   g_return_val_if_fail (G_IS_MEMORY_INPUT_STREAM (stream), -1);
 252
 253   return stream->priv->len;
 254 }
 255
 256 static gssize
 257 g_memory_input_stream_skip (GInputStream              *stream,
 258                             gsize                      count,
 259                             GCancellable              *cancellable,
 260                             GError                   **error)
 261 {
 262   GMemoryInputStream *memory_stream;
 263   GMemoryInputStreamPrivate *priv;
 264
 265   memory_stream = G_MEMORY_INPUT_STREAM (stream);
 266   priv = memory_stream->priv;
 267
 268   count = MIN (count, priv->len - priv->pos);
 269   priv->pos += count;
 270
 271   return count;
 272
 273
 274 }
 275
 276 static gboolean
 277 g_memory_input_stream_close (GInputStream *stream,
 278                              GCancellable *cancellable,
 279                              GError      **error)
 280 {
 281   return TRUE;
 282 }
 283
 284 static void
 285 g_memory_input_stream_read_async (GInputStream              *stream,
 286                                   void                      *buffer,
 287                                   gsize                      count,
 288                                   int                        io_priority,
 289                                   GCancellable              *cancellable,
 290                                   GAsyncReadyCallback        callback,
 291                                   gpointer                   user_data)
 292 {
 293   GSimpleAsyncResult *simple;
 294   gssize nread;
 295
 296   nread =  g_memory_input_stream_read (stream,  buffer, count, cancellable, NULL);
 297   simple = g_simple_async_result_new (G_OBJECT (stream),
 298                                       callback,
 299                                       user_data,
 300                                       g_memory_input_stream_read_async);
 301   g_simple_async_result_set_op_res_gssize (simple, nread);
 302   g_simple_async_result_complete_in_idle (simple);
 303   g_object_unref (simple);
 304 }
 305
 306 static gssize
 307 g_memory_input_stream_read_finish (GInputStream              *stream,
 308                                    GAsyncResult              *result,
 309                                    GError                   **error)
 310 {
 311   GSimpleAsyncResult *simple;
 312   gssize nread;
 313
 314   simple = G_SIMPLE_ASYNC_RESULT (result);
 315   g_assert (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_read_async);
 316
 317   nread = g_simple_async_result_get_op_res_gssize (simple);
 318   return nread;
 319 }
 320
 321 static void
 322 g_memory_input_stream_skip_async (GInputStream              *stream,
 323                                   gsize                      count,
 324                                   int                        io_priority,
 325                                   GCancellable              *cancellable,
 326                                   GAsyncReadyCallback        callback,
 327                                   gpointer                   user_data)
 328 {
 329   GSimpleAsyncResult *simple;
 330   gssize nskipped;
 331
 332   nskipped = g_memory_input_stream_skip (stream, count, cancellable, NULL);
 333   simple = g_simple_async_result_new (G_OBJECT (stream),
 334                                       callback,
 335                                       user_data,
 336                                       g_memory_input_stream_skip_async);
 337   g_simple_async_result_set_op_res_gssize (simple, nskipped);
 338   g_simple_async_result_complete_in_idle (simple);
 339   g_object_unref (simple);
 340 }
 341
 342 static gssize
 343 g_memory_input_stream_skip_finish (GInputStream              *stream,
 344                                    GAsyncResult              *result,
 345                                    GError                   **error)
 346 {
 347   GSimpleAsyncResult *simple;
 348   gssize nskipped;
 349
 350   simple = G_SIMPLE_ASYNC_RESULT (result);
 351   g_assert (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_skip_async);
 352
 353   nskipped = g_simple_async_result_get_op_res_gssize (simple);
 354   return nskipped;
 355 }
 356
 357 static void
 358 g_memory_input_stream_close_async (GInputStream              *stream,
 359                                    int                        io_priority,
 360                                    GCancellable              *cancellable,
 361                                    GAsyncReadyCallback        callback,
 362                                    gpointer                   user_data)
 363 {
 364   GSimpleAsyncResult *simple;
 365
 366   simple = g_simple_async_result_new (G_OBJECT (stream),
 367                                       callback,
 368                                       user_data,
 369                                       g_memory_input_stream_close_async);
 370   g_simple_async_result_complete_in_idle (simple);
 371   g_object_unref (simple);
 372 }
 373
 374 static gboolean
 375 g_memory_input_stream_close_finish (GInputStream              *stream,
 376                                     GAsyncResult              *result,
 377                                     GError                   **error)
 378 {
 379   return TRUE;
 380 }
 381
 382 static goffset
 383 g_memory_input_stream_tell (GSeekable *seekable)
 384 {
 385   GMemoryInputStream *memory_stream;
 386   GMemoryInputStreamPrivate * priv;
 387
 388   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 389   priv = memory_stream->priv;
 390
 391   return priv->pos;
 392 }
 393
 394 static
 395 gboolean g_memory_input_stream_can_seek (GSeekable *seekable)
 396 {
 397   return TRUE;
 398 }
 399
 400 static gboolean
 401 g_memory_input_stream_seek (GSeekable       *seekable,
 402                             goffset          offset,
 403                             GSeekType        type,
 404                             GCancellable    *cancellable,
 405                             GError         **error)
 406 {
 407   GMemoryInputStream *memory_stream;
 408   GMemoryInputStreamPrivate * priv;
 409   goffset absolute;
 410
 411   memory_stream = G_MEMORY_INPUT_STREAM (seekable);
 412   priv = memory_stream->priv;
 413
 414   switch (type) {
 415
 416     case G_SEEK_CUR:
 417       absolute = priv->pos + offset;
 418       break;
 419
 420     case G_SEEK_SET:
 421       absolute = offset;
 422       break;
 423
 424     case G_SEEK_END:
 425       absolute = priv->len + offset;
 426       break;
 427
 428     default:
 429       g_set_error (error,
 430                    G_IO_ERROR,
 431                    G_IO_ERROR_INVALID_ARGUMENT,
 432                    "Invalid GSeekType supplied");
 433
 434       return FALSE;
 435   }
 436
 437   if (absolute < 0 || absolute > priv->len)
 438     {
 439       g_set_error (error,
 440                    G_IO_ERROR,
 441                    G_IO_ERROR_INVALID_ARGUMENT,
 442                    "Invalid seek request");
 443       return FALSE;
 444     }
 445
 446   priv->pos = absolute;
 447
 448   return TRUE;
 449 }
 450
 451 static gboolean
 452 g_memory_input_stream_can_truncate (GSeekable *seekable)
 453 {
 454   return FALSE;
 455 }
 456
 457 static gboolean
 458 g_memory_input_stream_truncate (GSeekable      *seekable,
 459                                 goffset          offset,
 460                                 GCancellable    *cancellable,
 461                                 GError         **error)
 462 {
 463   g_set_error (error,
 464                G_IO_ERROR,
 465                G_IO_ERROR_NOT_SUPPORTED,
 466                "Cannot seek on GMemoryInputStream");
 467   return FALSE;
 468 }
 469
 470 #define __G_MEMORY_INPUT_STREAM_C__
 471 #include "gioaliasdef.c"
 472
 473 /* vim: ts=2 sw=2 et */